5l/6l/8l: add support for netbsd signature note section

R=m4dh4tt3r, jsing, rsc
CC=golang-dev
https://golang.org/cl/5493068

diff --git a/src/cmd/5l/asm.c b/src/cmd/5l/asm.c
index f7fa688be19dde916bc3a693dfe0fea1cd7052b0..8ec8935ffb972f2a71570071ead3ead7ce75beac 100644 (file)
--- a/src/cmd/5l/asm.c
+++ b/src/cmd/5l/asm.c
@@ -73,6 +73,7 @@ enum {
        ElfStrShstrtab,
        ElfStrRelPlt,
        ElfStrPlt,
+       ElfStrNoteNetbsdIdent,
        NElfStr
 };
 
@@ -164,6 +165,8 @@ doelf(void)
        elfstr[ElfStrText] = addstring(shstrtab, ".text");
        elfstr[ElfStrData] = addstring(shstrtab, ".data");
        elfstr[ElfStrBss] = addstring(shstrtab, ".bss");
+       if(HEADTYPE == Hnetbsd)
+               elfstr[ElfStrNoteNetbsdIdent] = addstring(shstrtab, ".note.netbsd.ident");
        addstring(shstrtab, ".rodata");
        addstring(shstrtab, ".gosymtab");
        addstring(shstrtab, ".gopclntab");
@@ -294,7 +297,7 @@ asmb(void)
 {
        int32 t;
        int a, dynsym;
-       uint32 fo, symo, startva;
+       uint32 fo, symo, startva, resoff;
        ElfEhdr *eh;
        ElfPhdr *ph, *pph;
        ElfShdr *sh;
@@ -336,6 +339,8 @@ asmb(void)
                        if(elfverneed)
                                elftextsh += 2;
                }
+               if(HEADTYPE == Hnetbsd)
+                       elftextsh += 1;
        }
 
        /* output symbol table */
@@ -371,7 +376,7 @@ asmb(void)
                cseek(symo);
                if(iself) {
                        if(debug['v'])
-                              Bprint(&bso, "%5.2f elfsym\n", cputime());
+                               Bprint(&bso, "%5.2f elfsym\n", cputime());
                        asmelfsym();
                        cflush();
                        cwrite(elfstrdat, elfstrsize);
@@ -455,6 +460,7 @@ asmb(void)
                eh = getElfEhdr();
                fo = HEADR;
                startva = INITTEXT - fo;        /* va of byte 0 of file */
+               resoff = ELFRESERVE;
                
                /* This null SHdr must appear before all others */
                newElfShdr(elfstr[ElfStrEmpty]);
@@ -487,7 +493,7 @@ asmb(void)
                        sh->addralign = 1;
                        if(interpreter == nil)
                                interpreter = linuxdynld;
-                       elfinterp(sh, startva, interpreter);
+                       resoff -= elfinterp(sh, startva, resoff, interpreter);
 
                        ph = newElfPhdr();
                        ph->type = PT_INTERP;
@@ -495,11 +501,24 @@ asmb(void)
                        phsh(ph, sh);
                }
 
+               if(HEADTYPE == Hnetbsd) {
+                       sh = newElfShdr(elfstr[ElfStrNoteNetbsdIdent]);
+                       sh->type = SHT_NOTE;
+                       sh->flags = SHF_ALLOC;
+                       sh->addralign = 4;
+                       resoff -= elfnetbsdsig(sh, startva, resoff);
+
+                       ph = newElfPhdr();
+                       ph->type = PT_NOTE;
+                       ph->flags = PF_R;
+                       phsh(ph, sh);
+               }
+
                elfphload(&segtext);
                elfphload(&segdata);
 
                /* Dynamic linking sections */
-               if (!debug['d']) {      /* -d suppresses dynamic loader format */
+               if(!debug['d']) {       /* -d suppresses dynamic loader format */
                        /* S headers for dynamic linking */
                        sh = newElfShdr(elfstr[ElfStrGot]);
                        sh->type = SHT_PROGBITS;
@@ -590,7 +609,7 @@ asmb(void)
                for(sect=segdata.sect; sect!=nil; sect=sect->next)
                        elfshbits(sect);
 
-               if (!debug['s']) {
+               if(!debug['s']) {
                        sh = newElfShdr(elfstr[ElfStrSymtab]);
                        sh->type = SHT_SYMTAB;
                        sh->off = symo;
@@ -632,7 +651,9 @@ asmb(void)
                a += elfwritehdr();
                a += elfwritephdrs();
                a += elfwriteshdrs();
-               a += elfwriteinterp();
+               a += elfwriteinterp(elfstr[ElfStrInterp]);
+               if(HEADTYPE == Hnetbsd)
+                       a += elfwritenetbsdsig(elfstr[ElfStrNoteNetbsdIdent]);
                if(a > ELFRESERVE)      
                        diag("ELFRESERVE too small: %d > %d", a, ELFRESERVE);
                break;

diff --git a/src/cmd/6l/asm.c b/src/cmd/6l/asm.c
index c3b2ba42f6c546b1b26249c1727bec174fa253a0..1169490b8065c26998d1ec66de58eda04467cb7b 100644 (file)
--- a/src/cmd/6l/asm.c
+++ b/src/cmd/6l/asm.c
@@ -707,7 +707,7 @@ asmb(void)
 {
        int32 magic;
        int a, dynsym;
-       vlong vl, startva, symo, dwarfoff, machlink;
+       vlong vl, startva, symo, dwarfoff, machlink, resoff;
        ElfEhdr *eh;
        ElfPhdr *ph, *pph;
        ElfShdr *sh;
@@ -778,6 +778,8 @@ asmb(void)
                        if(elfverneed)
                                elftextsh += 2;
                }
+               if(HEADTYPE == Hnetbsd)
+                       elftextsh += 1;
                break;
        case Hwindows:
                break;
@@ -879,6 +881,7 @@ asmb(void)
 
                eh = getElfEhdr();
                startva = INITTEXT - HEADR;
+               resoff = ELFRESERVE;
 
                /* This null SHdr must appear before all others */
                newElfShdr(elfstr[ElfStrEmpty]);
@@ -925,7 +928,7 @@ asmb(void)
                                        break;
                                }
                        }
-                       elfinterp(sh, startva, interpreter);
+                       resoff -= elfinterp(sh, startva, resoff, interpreter);
 
                        ph = newElfPhdr();
                        ph->type = PT_INTERP;
@@ -933,11 +936,24 @@ asmb(void)
                        phsh(ph, sh);
                }
 
+               if(HEADTYPE == Hnetbsd) {
+                       sh = newElfShdr(elfstr[ElfStrNoteNetbsdIdent]);
+                       sh->type = SHT_NOTE;
+                       sh->flags = SHF_ALLOC;
+                       sh->addralign = 4;
+                       resoff -= elfnetbsdsig(sh, startva, resoff);
+
+                       ph = newElfPhdr();
+                       ph->type = PT_NOTE;
+                       ph->flags = PF_R;
+                       phsh(ph, sh);
+               }
+
                elfphload(&segtext);
                elfphload(&segdata);
 
                /* Dynamic linking sections */
-               if (!debug['d']) {      /* -d suppresses dynamic loader format */
+               if(!debug['d']) {       /* -d suppresses dynamic loader format */
                        /* S headers for dynamic linking */
                        sh = newElfShdr(elfstr[ElfStrGot]);
                        sh->type = SHT_PROGBITS;
@@ -1061,7 +1077,7 @@ asmb(void)
                for(sect=segdata.sect; sect!=nil; sect=sect->next)
                        elfshbits(sect);
 
-               if (!debug['s']) {
+               if(!debug['s']) {
                        sh = newElfShdr(elfstr[ElfStrSymtab]);
                        sh->type = SHT_SYMTAB;
                        sh->off = symo;
@@ -1107,7 +1123,9 @@ asmb(void)
                a += elfwritehdr();
                a += elfwritephdrs();
                a += elfwriteshdrs();
-               a += elfwriteinterp();
+               a += elfwriteinterp(elfstr[ElfStrInterp]);
+               if(HEADTYPE == Hnetbsd)
+                       a += elfwritenetbsdsig(elfstr[ElfStrNoteNetbsdIdent]);
                if(a > ELFRESERVE)      
                        diag("ELFRESERVE too small: %d > %d", a, ELFRESERVE);
                break;

diff --git a/src/cmd/8l/asm.c b/src/cmd/8l/asm.c
index 3612c2bf2a09d0c98a2e3cf31c22a7e4be4703d5..7799e3f1e2e2511df4d6dd8e66425eae7b4c15ca 100644 (file)
--- a/src/cmd/8l/asm.c
+++ b/src/cmd/8l/asm.c
@@ -92,6 +92,7 @@ enum {
        ElfStrPlt,
        ElfStrGnuVersion,
        ElfStrGnuVersionR,
+       ElfStrNoteNetbsdIdent,
        NElfStr
 };
 
@@ -528,6 +529,8 @@ doelf(void)
        elfstr[ElfStrText] = addstring(shstrtab, ".text");
        elfstr[ElfStrData] = addstring(shstrtab, ".data");
        elfstr[ElfStrBss] = addstring(shstrtab, ".bss");
+       if(HEADTYPE == Hnetbsd)
+               elfstr[ElfStrNoteNetbsdIdent] = addstring(shstrtab, ".note.netbsd.ident");
        addstring(shstrtab, ".elfdata");
        addstring(shstrtab, ".rodata");
        addstring(shstrtab, ".gosymtab");
@@ -661,7 +664,7 @@ asmb(void)
 {
        int32 v, magic;
        int a, dynsym;
-       uint32 symo, startva, dwarfoff, machlink;
+       uint32 symo, startva, dwarfoff, machlink, resoff;
        ElfEhdr *eh;
        ElfPhdr *ph, *pph;
        ElfShdr *sh;
@@ -715,6 +718,8 @@ asmb(void)
                        if(elfverneed)
                                elftextsh += 2;
                }
+               if(HEADTYPE == Hnetbsd)
+                       elftextsh += 1;
        }
 
        symsize = 0;
@@ -761,7 +766,7 @@ asmb(void)
                default:
                        if(iself) {
                                if(debug['v'])
-                                      Bprint(&bso, "%5.2f elfsym\n", cputime());
+                                       Bprint(&bso, "%5.2f elfsym\n", cputime());
                                asmelfsym();
                                cflush();
                                cwrite(elfstrdat, elfstrsize);
@@ -932,6 +937,7 @@ asmb(void)
        Elfput:
                eh = getElfEhdr();
                startva = INITTEXT - HEADR;
+               resoff = ELFRESERVE;
 
                /* This null SHdr must appear before all others */
                newElfShdr(elfstr[ElfStrEmpty]);
@@ -978,7 +984,7 @@ asmb(void)
                                        break;
                                }
                        }
-                       elfinterp(sh, startva, interpreter);
+                       resoff -= elfinterp(sh, startva, resoff, interpreter);
 
                        ph = newElfPhdr();
                        ph->type = PT_INTERP;
@@ -986,11 +992,24 @@ asmb(void)
                        phsh(ph, sh);
                }
 
+               if(HEADTYPE == Hnetbsd) {
+                       sh = newElfShdr(elfstr[ElfStrNoteNetbsdIdent]);
+                       sh->type = SHT_NOTE;
+                       sh->flags = SHF_ALLOC;
+                       sh->addralign = 4;
+                       resoff -= elfnetbsdsig(sh, startva, resoff);
+
+                       ph = newElfPhdr();
+                       ph->type = PT_NOTE;
+                       ph->flags = PF_R;
+                       phsh(ph, sh);
+               }
+
                elfphload(&segtext);
                elfphload(&segdata);
 
                /* Dynamic linking sections */
-               if (!debug['d']) {      /* -d suppresses dynamic loader format */
+               if(!debug['d']) {       /* -d suppresses dynamic loader format */
                        /* S headers for dynamic linking */
                        sh = newElfShdr(elfstr[ElfStrGot]);
                        sh->type = SHT_PROGBITS;
@@ -1114,7 +1133,7 @@ asmb(void)
                for(sect=segdata.sect; sect!=nil; sect=sect->next)
                        elfshbits(sect);
 
-               if (!debug['s']) {
+               if(!debug['s']) {
                        sh = newElfShdr(elfstr[ElfStrSymtab]);
                        sh->type = SHT_SYMTAB;
                        sh->off = symo;
@@ -1167,7 +1186,9 @@ asmb(void)
                a += elfwritehdr();
                a += elfwritephdrs();
                a += elfwriteshdrs();
-               a += elfwriteinterp();
+               a += elfwriteinterp(elfstr[ElfStrInterp]);
+               if(HEADTYPE == Hnetbsd)
+                       a += elfwritenetbsdsig(elfstr[ElfStrNoteNetbsdIdent]);
                if(a > ELFRESERVE)      
                        diag("ELFRESERVE too small: %d > %d", a, ELFRESERVE);
                break;

diff --git a/src/cmd/ld/elf.c b/src/cmd/ld/elf.c
index 00cfc8c8c9ea11d4aa823c75ae8b016eeda95d74..de9e6b8541e27fb8ec1e64d8fd7575b033ac5e63 100644 (file)
--- a/src/cmd/ld/elf.c
+++ b/src/cmd/ld/elf.c
@@ -318,29 +318,77 @@ elfwritedynentsymsize(Sym *s, int tag, Sym *t)
 }
 
 int
-elfwriteinterp(void)
+elfinterp(ElfShdr *sh, uint64 startva, uint64 resoff, char *p)
 {
        int n;
 
-       if(interp == nil)
-               return 0;
-
+       interp = p;
        n = strlen(interp)+1;
-       cseek(ELFRESERVE-n);
-       cwrite(interp, n);
+       sh->addr = startva + resoff - n;
+       sh->off = resoff - n;
+       sh->size = n;
+
        return n;
 }
 
-void
-elfinterp(ElfShdr *sh, uint64 startva, char *p)
+int
+elfwriteinterp(vlong stridx)
+{
+       ElfShdr *sh = nil;
+       int i;
+
+       for(i = 0; i < hdr.shnum; i++)
+               if(shdr[i]->name == stridx)
+                       sh = shdr[i];
+       if(sh == nil || interp == nil)
+               return 0;
+
+       cseek(sh->off);
+       cwrite(interp, sh->size);
+       return sh->size;
+}
+
+// Defined in NetBSD's sys/exec_elf.h
+#define ELF_NOTE_TYPE_NETBSD_TAG       1
+#define ELF_NOTE_NETBSD_NAMESZ         7
+#define ELF_NOTE_NETBSD_DESCSZ         4
+#define ELF_NOTE_NETBSD_NAME           "NetBSD\0\0"
+#define ELF_NOTE_NETBSD_VERSION                599000000       /* NetBSD 5.99 */
+
+int
+elfnetbsdsig(ElfShdr *sh, uint64 startva, uint64 resoff)
 {
        int n;
 
-       interp = p;
-       n = strlen(interp)+1;
-       sh->addr = startva + ELFRESERVE - n;
-       sh->off = ELFRESERVE - n;
+       n = sizeof(Elf_Note) + ELF_NOTE_NETBSD_NAMESZ + ELF_NOTE_NETBSD_DESCSZ + 1;
+       n += resoff % 4;
+       sh->addr = startva + resoff - n;
+       sh->off = resoff - n;
        sh->size = n;
+
+       return n;
+}
+
+int
+elfwritenetbsdsig(vlong stridx) {
+       ElfShdr *sh = nil;
+       int i;
+
+       for(i = 0; i < hdr.shnum; i++)
+               if(shdr[i]->name == stridx)
+                       sh = shdr[i];
+       if(sh == nil)
+               return 0;
+
+       // Write Elf_Note header followed by NetBSD string.
+       cseek(sh->off);
+       LPUT(ELF_NOTE_NETBSD_NAMESZ);
+       LPUT(ELF_NOTE_NETBSD_DESCSZ);
+       LPUT(ELF_NOTE_TYPE_NETBSD_TAG);
+       cwrite(ELF_NOTE_NETBSD_NAME, 8);
+       LPUT(ELF_NOTE_NETBSD_VERSION);
+
+       return sh->size;
 }
 
 extern int nelfsym;

diff --git a/src/cmd/ld/elf.h b/src/cmd/ld/elf.h
index c63df22417f163bc28102af98d1be402f3a0e3a4..690ade9753dbea83ab364be0ba3ecd1bb7a598da 100644 (file)
--- a/src/cmd/ld/elf.h
+++ b/src/cmd/ld/elf.h
@@ -968,8 +968,10 @@ extern     int     numelfphdr;
 extern int     numelfshdr;
 extern int     iself;
 extern int     elfverneed;
-int    elfwriteinterp(void);
-void   elfinterp(ElfShdr*, uint64, char*);
+int    elfinterp(ElfShdr*, uint64, uint64, char*);
+int    elfwriteinterp(vlong);
+int    elfnetbsdsig(ElfShdr*, uint64, uint64);
+int    elfwritenetbsdsig(vlong);
 void   elfdynhash(void);
 ElfPhdr* elfphload(Segment*);
 ElfShdr* elfshbits(Section*);